“There has been a ton of speculation in the media and in user forums over what’s going on with the iPhone 5S accelerometer: see CNET, Gizmodo, ExtremeTech, Apple Support Communities, or MacRumors,” Eagle Jones blogs for RealityCap. “In short, apps that use the accelerometer to sense device tilt are showing errors of as much as 5-6 degrees off level, when these apps worked fine with previous iOS devices. This can be seen in many games as well as tools like level apps, including Apple’s built-in compass/level app.”

“People are asking whether this is a hardware shortcoming, manufacturing issue, or software problem. Quite definitely, the answer is that these issues exist due to hardware design,” Jones writes. “The Chipworks teardown of the iPhone 5S identified the accelerometer as the Bosch Sensortech BMA220. Previous Apple devices have been reported to use ST parts, such as the LIS331DLH in the iPhone 5 (according to iFixit).”

“What can developers who depend on reasonable accuracy from the accelerometer do? The good news is that a large component of the bias error in the accelerometer doesn’t change. Thus it is possible to work around the problem by incorporating a calibration procedure into apps,” Jones writes. “This procedure would ask the user to place the device in different orientations to determine the accelerometer bias. Apps can then subtract this measured bias from the data coming from the accelerometer to get a corrected reading.”

Derek, ever since Cocoa was released, there is virtually NO sanctioned direct access to hardware either on Mac, iOS, or other future platforms. The whole idea is that you work with a defined common platform, and the classes optimize what you want done into the best way to do it with that particular hardware.

That makes perfect sense! I simply have zero experience with how iOS programs are coded. I now for OS X Apple insisted that developers stick to the APIs, no direct access to the machine language, etc. That hasn’t stopped certain people! I know Andrew Welch over at Ambrosia Software. He accomplishes much of his magical coding by using assembly language, skipping Apple’s code calls. But he’s an exception.

More than 1%… Although my 5S is off by -1%… I have hears more reports of it being off, than correct. So I can’t say what the percentages are, but suspect if %80 of iPhone buyers are like my wife, they could care less about the “level” and only care about the GPS being correct, which there isn’t a problem with GPS. The only gripers are the ones who know to look for it. So again, I can’t believe it’s 1%, I suspect it’s more like 20%.

Derek, ever since Cocoa was released, there is virtually NO sanctioned direct access to hardware either on Mac, iOS, or other future platforms. The whole idea is that you work with a defined common platform, and the classes optimize what you want done into the best way to do it with that particular hardware.

Mine and my wife’s are both affected by this. Hers was shipped from China on Sept. 26. Mine was bought in Florida Sept. 28, so they were clearly not from the same manufacturing batch. I’ve spent about $10,000 on Apple products in the last 8 years and never received one with a hardware defect before.
I can wait for a fix, it’s not as though I use it for woodworking. But if Apple continues to ignore the issue I will be making a Genius Bar appointment for an exchange.

I have repeatedly compared my 5s to my wifes 5. The five was right on level and compass for a year. Since 7-0.2 it shows as much error as the 5s. I know that does not agree with what I keep reading but it is happening for sure. Both are off up to 5 degrees compass, level not so much. Has anyone else compared those two?

I know a few people with a iPhone 5. My mom is one of them and her 5 is of by a degree long ways. While my friends 5 isn’t off. My 5s is off by a degree.
I had to check any before cuz I never even knew about the level let alone tested one before I heard of this
So I’ve never tried my old 5 or anyone else’s level before this was in media . But I have compared a few to my 5s since I heard of this.
On the same boat as someone stated above, I’m keeping mine. Not a deal breaker. I did already take my phone into a genius after a apple engineer suggested I did about a week and Half ago. The engineer said he hasn’t heard of the problem. The genius 2 days later at my appointment said “its a known issue” I told him what engineer said and he said thats crazy and even he knew.he then asked me to wait and went into the back and came back after maybe 5 mins and claimed he tried 5 iPhone 5s’s and even a few 5’s and they were all a little off. He said it’s prolly a software issue And said he would think a update would come out soon to fix. Then he offered to give me a refund being that I bought it there if I wanted. Said nah. I’m good.
Hearing people hear who claim to not have the problem I’m kinda like wtf. Level is no big deal. And if this wasn’t my phone I’d probably be like, what’s the big deal. Don’t be anal about it. But here I am wanting to be picky. If it’s not happening to everybody then I don’t want it to happen to mine either.
These article gotta keep coming and reminding me.